Alcohol consumption and social behaviors have a complex relationship. Some view alcoholic beverages as 'social lubricants". On the other hand, alcohol abuse and alcoholism lead to severe social and marital problems, including neglect, abuse and aggression. Alcohol consumption is often regarded as a way to overcome sadness following loss of friend or spouse, and severe alcohol abuse often follows divorce or death of friend. Could the co-occurrence of alcohol and social problems be not a coincidence, but have an underlying biological mechanism? This application proposes to use a novel rodent model to address this question. More specifically, we hypothesize that neurochemical mechanisms regulating social behaviors and alcohol intake overlap and involve specific receptors to vasopressin and corticotropin-relasing factor (CRF). The link between social behavior and alcohol abuse has been difficult to address using animal models because most laboratory rodents don't display strong affiliative behaviors and don't show high alcohol drinking. However, the situation has changed with increased research on prairie and pine voles, microtine rodents that do display strong affiliative behaviors. Intriguingly, our pilot studies indicate that prairie voles show high alcohol consumption in a two-bottle preference test. Being the first identified genetically heterogeneous non-selectively bred social rodent model of subjects with high alcohol consumption, the prairie voles offer a unique opportunity to address the mechanisms of interactions between social and biological mechanisms leading to high alcohol intake. This exploratory grant proposes to begin addressing these mechanisms. In particular, we propose to address social, developmental, genetic and molecular mechanisms leading to high alcohol intake in four specific aims: 1) To investigate the extent of correlation between social affiliation and alcohol drinking in voles;2) To investigate whether pair-housed and isolate-housed peri-adolescent and adult prairie voles consume different amounts of alcohol;3) To investigate whether the correlation between high alcohol intake and social affiliation is genetically determined;4) To investigate whether vasopressin V1a and CRF2 receptors contribute to genetic predisposition to high alcohol drinking and measures of social affiliation. Understanding mechanisms leading to high alcohol consumption in this new rodent model could lay ground for innovative approaches to treatment of alcoholism and alcohol abuse-related disorders taking into account the social-, age- and genotype-specific particularities of an individual patient.